bio synoptic revision

Question 1

explain how triglycerides are formed

Answer 1

a condensation reaction between a glycerol and three fatty acids to from ester bonds between them and producing 3 water molecules.

Question 2

bats question

Answer 2

bats use more energy

Question 3

evaulate question

Answer 3

no statistical test to show difference

Question 4

how to calculate the volume of oxygen in a mammal (haemoglobin)

Answer 4

• convert mass and volume into correct units
• the do volume/ mass
• then if its asking for ‘per gram’ then do 0.01/ the amount for your answer.

Question 5

The tissues of the shrew have a higher rate of oxygen consumption per gram of body tissue than the elephant. There is an advantage to the shrew in having haemoglobin with a dissociation curve in the position shown. Explain this advantage.

Answer 5

at lower PPo2 the shrew has a lower affinity for oxygen, so oxyhaemoglobin disassociates more readily to respiring tissues . so high respiration and metabollic rate .

Question 6

Describe the relationship between the size of mammals and the oxygen dissociation curves of their haemoglobin.

Answer 6

the smaller the mammal the lower the affinity for oxygen. so graph would be more to the right

Question 7

Suggest how these differences allow the mouse to have a higher metabolic rate than the horse.

Answer 7

• mouse has a lower affinity for O2.
• so at low PP o2 , oxyhaemoglobin disassociate more readily to respiring tissue cells. so higher metabolic and respiration rate

Question 8

how does blood go from the kidney to the blood

Question 9

how does tissue fluid return to the blood

Answer 9

the water in the tissue fluid moves back into the capillary by osmosis due to a water potential gradient between the tissue fluid and the blood. and then the lymph (any remaining tissue fluid) is drained into lymphatic system then eventually back into blood

Question 10

how does blood transport in a circulatory system.

Answer 10

• deoxygenated blood enters the heart through the vena carva.
• then into the right atrium. then thorugh the atrio ventricular valve into the right ventricle.
• then the blood moves through the semi lunar valve into the pulmonary artery
• then the blood moves into thelungs and gets oxygenated and back into the heart through the ,pulmonary vein into the left atrium
• blood then travells through the atrioventricular valve into the left ventricle .
• then through the semi lunar valve into the aorta which then takes blood to the rest of the body .

Question 11

describe the digestion of proteins

Answer 11

• peptide bonds get hydrolysed.
• endopeptidase hydrolyses polypeptides into smaller polypeptide chains
• exopeptidase produces dipeptides
• then dipeptidase hydrolyses them dipeptides into single amino acids.

Question 12

describe transcribtion

Answer 12

• DNA helicase breaks h-bonds into 2 strands, but only one strand can act as a template.
• then free RNA nucleotides complimentary base pair with template strand due to base pairings rule
• RNA polymerase joins free RNA nucleotides together through condensation reaction forming phosphodiester bonds between them.
• pre-mRNA is spliced to remove introns

Question 13

dillution question

Answer 13

if you dilute it 20 times youll be able to see cells clearly but if you dillute it a further to times you wont be able to see the cells.

Question 14

describe HIV replication

Answer 14

-protein on HIV binds to the protein in T-H cell.
-capsid fuses into cell surface membrane and viral RNA and HIV enzymes are released into the TH cell.
reverse transcriptase (HIV enzymes) converts viral RNA into cDNA using host nucleotides
-cDNA is then inserted into nucleus -person is now infected.
-transcriptase of viral cDNA into viral mRNA. which is translated to produce HIV proteins.
-the infected TH cell starts to produce new HIV particles.
-particles break away from the TH cell with a section of host cell surface membrane which forms their lipid envelope, with TH receptor proteins embedded into it.
-overtime this leads to a reduction in TH cells

Question 15

describe the structure of HIV

Answer 15

• two strands of RNA and enzymes (reverse transcriptase)
• conatined in a capsid
• which is surrounded by a lipid envelope with glycoproteins embedded

Question 16

A student carried out the Benedict’s test. Suggest a method, other than using a colorimeter, that this student could use to measure the quantity of reducing sugar in a solution.

Answer 16

• filter and dry precipitate

- find mass/weight

Question 17

Describe how natural selection occurs

Answer 17

• variation due to mutation
• different abiotic/biotic conditions
• leads to a selection in advantageous alleles
• differential reproductive success- the selected organisms survive and reproduce.
• so allele frequency increases over a period of time

Question 18

How does the student measure water movement in Celery

Answer 18

-

Question 19

Describe why the gas exchange in fish are more than humans

Question 20

describe the ELISA test

Answer 20

• test contains monoclonal antibodies, which detect a certain substance in a liquid sample using monoclonal antibodies
• monoclonal antibodies are fixed to the surface of the test well
• sample containing molecule to be detected binds to the antibody due to complimentary shapes
• second monoclonal antibodies with enzymes attached to it are added to the sample and bind to the molecule.
• then is washed so any unbound antibodies with enzymes are washed away and removed from the test well
• substrate is added -chemical colour change visible
• colour change from pink to blue is a positive result -confirming the presence of the molecule
• if colour remains pink then negative result

Question 21

what is a monoclonal antibody

Answer 21

it is identical copies of one antibody

Question 22

what is the elisa test used for?

Answer 22

to test for the diagnose HIV

Question 23

what are some uses for monoclonal antibodies

Answer 23

-research
-immuno assays: pregnancy testing kits / ELISA tests
-diagnosis: shows the presence of an particular antigen
-killing specific cells
-

Question 24

celery question:

give two measurements he made to calculate the rate of water movement

Answer 24

• initial and final mass of beaker and of all contents

- number of groups of xylem vessels

Question 25

give a reason for adding a layer of oil to the water in the beaker

Answer 25

prevent evaporation/water loss

Question 26

explain why the coloured water moved up the stalks

Answer 26

• water is transpired from the celery.-water protential gradient creates tension and pulls water up
• hydrogen bonds maintains column

Question 27

describe how she should ensure she handled the scalpel safely during this procedure.

Answer 27

• cut away from the body

- against a flat surface

Question 28

Q5.5 celery one

Answer 28

• median
• presence of outliers (80/70)
• 41

Question 29

Describe anaphase

Answer 29

• spindle fibres shorten

- centromere splits and sister chromatids are separated and pulled to opposite poles